Sarasota’s malaria scare brought new tactics in mosquito control
Ground-based spraying nearly doubled in the county's targeted approach; though a dry summer helped mitigate costs, an official says.
With seven documented cases of malaria reported in Sarasota County this year, the county’s Mosquito Management Services team spent the summer on high alert.
The cases were reported in May, June and July, prompted by mosquitos carrying the Plasmodium vivax infection.
Mosquito Management Services manager Wade Brennan said the team increased its spray treatments in response to the outbreak, but dry weather in the first half of the summer also helped control the threat. Brennan said extra treatments focused on high-risk areas in North Sarasota.
“So, with malaria, we were dealing with a smaller focused area. And we were dealing with a species that doesn't fly that far,” Brennan said. “And so, what that allowed us to do is we changed our focus [from] more wider spread throughout the entire county to northern Sarasota. And we were able to put the boots on the ground and really get into those wood lots and also those trenches, the canals, areas like that.”
Along with the malaria threat, effects of Hurricane Ian and Hurricane Idalia also increased the risk of mosquito-borne diseases ahead of and following the unusually dry summer. This resulted in an increased number of spray treatments in the county, with 51 truck missions completed in the 2023 fiscal year from Oct. 1, 2022- Sept. 30, 2023.
The previous four years averaged 26 truck missions a year while aerial missions averaged 32. The 2023 fiscal year saw aerial missions increase to 35.
As treatments increased, so did the cost, but Brennen said the drought helped to offset the expenses. For the 2023 fiscal year the county contracted out spraying services and purchased pesticides that cost a total of $1,070,000. The total expenses in 2022 was $870,000.
The team uses a combination of adulticides and larvicides for treatment, and they rotate them to reduce chances of resistance. Pesticides used include: Deltamethrin, Etofenprox, Naled, Permethrin/Piperonyl Butoxide, Sumithrin, Bacillus thuringiensis israelensis, Bacillus sphaericus, Spinosad, Methoprene, Mineral Oil (Cocobear) and Mosquito Fish.
Brennan says 90% of their treatments typically utilize larvicides, meaning they do not kill other bugs but rather mosquito larvae.
“They're very targeted specific to mosquitoes only,” Brennan said. “But our adulticides do have other insects that they can kill, so that's why we apply at night. So, we're targeting and making sure that it's not affecting our local pollinators with our bees, our butterflies, all our beneficial insects.”
Brennan notes that while the malaria threat has passed, the area now enters the annual timeframe for increased West Nile threats. To help reduce risks of disease, he recommends people take protective measures.
“Our biggest problem is getting into people's backyards and controlling those mosquitoes, we actually need everybody to do so for us so we can focus on the larger neighborhood or area treatment,” he said. “We need everybody to make sure to dump and drain any kind of container or standing water around their house. We also need everybody to make sure that they keep up on self-protection against mosquito bites.”
Brennen recommends wearing long, loosely fitting clothing and using repellant approved by the Centers for Disease Control and Prevention. Residents can also request assistance and mosquito management services by calling 311.
For information on Sarasota County Mosquito Management Services, visit https://bit.ly/3rKW114.
Sarah Owens in a reporter for the Community News Collaborative. Connect with her at firstname.lastname@example.org.